I installed a Akropovic full titanium exhaust system, a BMC re-usable high-flow air filter, and DynoJet's Power Commander (PCV) and Autotune products on my 2012 R1200GS and went to the dyno room. The results:

1) I did three stock runs and the best was 104 rear wheel HP ("rwhp") and 82 ft-lbs of torque (the other two were 103 and change rwhp). The best post-mod run was 111 rwhp and 86 ft-lbs of torque (with a number of 110's). There was one run that actually hit 112 rwhp but it was spikey above 7,000 rpm (unlike the other runs which were more or less smooth), so we eliminated it as an anomaly. These readings, and all the readings below, are "corrected" to a reference external temperature and humidity baseline for consistency.

2) Of the 7 rwhp gain, about half was due to the Akropovic exhaust and the other half due to the Power Commander.

3) The high-flow BMC air filter provided no performance gains to the subject motorcycle. In fact, of the 20+ runs we did, only two were with the stock filter and it was one of these runs where the bike achieved 111 rwhp. If you're buying the filter for its reusability and wet weather utility improvements over the OEM paper filter, then you're buying it for the right reasons. If you've drank the Kool-Aid and are buying it to give you increased power, you've been suckered.

4) The airbox snorkel appears to be an integral part of the air intake design. Out of curiosity, we removed the snorkel, thinking it may restrict air flow through the already quite small air filter. We did two runs and both were in the 105 rwhp range, down 5-6 rwhp from our high run.

5) Removing the db-killer (baffle) from the Akrapovic slip-on had no discernible impact on performance.

6) 95% of GS/GSA owners - and I put myself in this category - would be satisfied going with just the Booster Plug or a similar ECU "fooling" mechanism. Only those that want that post-6000 rpm "turbo boost" effect need bother with the PC-V. That being said, a PCV without the Autotune can be gotten for $300 street price, and this is really all you need providing you can find a map that matches your motorcycle configuration.

7) The boxer engine was very temperature sensitive - the best readings we achieved in the "high four bar" temperature range. Runs in the three and five bar temperature ranges consistently turned in sub-par results.

The Long Story

Two things bothered me about the mechanical performance of my new R1200GS - the low speed lurching and decel popping, and the inherent vibration that kicks in at at 4200 rpm. "Bother" might be a strong term because both issues were more minor irritants rather than game breakers, but they were two issues I wanted to address. I had no urge to make this bike a track demon, so high-rpm horsepower gains weren't overly influential in my decision.

I previously had a Moto Guzzi Stelvio that had similar engine performance issues caused by leaning fueling, and people raved about how the PC-V gave the bike a completely new character, so I knew that was a (expensive) solution to the first problem of low-RPM performance. However, through this forum I also because of the Booster Plug, which at $150 was a much more cost effective solution to the same problem, but did not address the 4200 rpm vibration issue. I had no urge to make this bike a track demon, so high-rpm horsepower gains weren't overly influential in my decision. Having time on my hands,

I decided to splurge for the Power Commander in the hopes of adding additional power in the mid-range to hopefully drop the rpms below 4200 at my highway cruising speed of 120 kmh. I paid $520 for the R1200GS PC-V and AT-300 dual-channel Autotune device from Revzilla after a price match. The AT-300 has two O2 sensors so I could tune each cylinder independent of the other. The other advantage of the Power COmmander is that it enables you to have two maps, so I can set one map for every-day use (towards the power side in the non-cruise range) and second, leaner map to improve fuel economy on longer highway journeys. Creating the second map would be a snap with the Autotune.

I will also add that I swapped the stock header and slip-on for Akropovic's full titanium exhaust system and added a BMC re-usable high-flow air filter. The logic behind the air filter mod was that if I was opening up the back end, I don't want the engine to be choked by the filter. The Akropovic exhaust was $1,150 from Revzilla and the BMC air filter was something like $40 from a Texas sportsbike shop. The Akro titanium exhaust system is amazingly light and eliminates the catalytic converter. Based on my crude kitchen scale measuring methodology, the 13 lb titanium system cut about 9 lbs off the stock exhaust system. As an added benefit, the catalytic converter will no longer be boiling my gear box oil.

Total performance improvement outlay rings in at $1,700 (ouch!).

Given I couldn't find any before-and-after comparisons on the 'net, I decided to suck it up and spend money for the extra dyno time to dyno the bike before I did my mods. I was also determined to quantify the impact of the BMC high-flow air filter. It cost me an extra $200 in dyno time, so donations are welcome (haha - just joking - but feel free to make donations to the running of this forum).

I went to Lentech Automotive Performance on August 31 with my stock R1200GS and did three initial dyno runs for the sole purpose of benchmarking the performance attributes of the mods I was going to make, namely the upgrade to the Akropovic titanium full exhaust and a high-flow after market air filter (I went with BMC, but actually had both to choose from). Lentech typically does sportbike dynoing because that is where the demand is, although they have done a few cruisers. My bike was the first dual sport to show up at the doorstep, and upon my return trip, it as the first bike caked in mud that showed up at their doorstep.

We did three pulls and all three were fairly consistent - 103, 104, and 103 rwhp, respectively, with all runs generating over 80 ft-lbs of torque. The two dyno operators were shocked at the level of torque the motor put out. They see very few bikes hit that mark, the last one being a souped up litre bike that put out 194 rwhp and just cracked the 80 mark.

Off I rode home to add my mods. The titanium full Akro system is pretty sweet. Installation was quite simple and I love the sound. It isn't much louder than stock, but has a lower grumble to it. I then installed the Power Commander and Autotune. This was a little more challenging as the there are six wires from each of the Bosch oxygen sensors to connect, as well as the Autotune/map switch. To compound matters, I have my Adventure Designs tool kit and FuzeBlock under the seat, so I had to innovatively jam the PCV/Autotune against the throttle linkage box under the tank. This entail taking body parts off and the big bolt on the left hand side that secures the tank to the bike. Note to readers: if you have to take this bolt out, make sure you don't have a full tank of gas!

The PCV comes with a map for the stock GS. Fortunately DynoJet had a map on its website for a US bike with a full Akro system and stock air filter, so I grabbed that. Turns out it was almost a perfect map for my bike.

After the installation of the mods was complete, I took the bike for a spin. My Fat Ass dyno certainly noticed the power pick-up as soon as it hit 6,000 rpm. The first time I cracked it wide open throttle, the bike nearly ripped the handlebars from my grip. It is literally like somebody threw the nitro switch at the engine crested 6,000 rpm. What an amazing feeling!

I went back to the dyno today, September 12. I was intending to do the following runs to determine the performance attribution of each mod:

1) Akro exhaust with BMC filter, PCV disconnected
2) Akro exhaust with BMC filter, PCV engaged and custom map
3) Setup as in 2) but with the OEM air filter

We did two runs for setup #1 and hit 107 rwhp, up about 3 from stock. I forgot to get the graph so I don't have the exact number or the torque number.

With setup #2 we did two at 107, two or three runs at 110 and another at 112 rwp. The 112 run was quite spikey from 6,000 to redline, looking like a Bart Simpson haircut. Because of this we decided to disregard the results. The dyno operators again expressed admiration at the amount of torque the engine put out.

This is about when we first noticed that the performance of the boxer engine was highly temperature dependent. The best runs came when the engine was in the "high four bar" range, meaning just before the oil temperature gauge moved to five bars. Runs at three bars were consistently about 10-12 rwhp low (i.e. in the high 90's). Runs at five bars were typically around 4-5 rwhp low of the highs. The optimum readings all came during runs when the engine had been in the four bar range for a bit, and typically in the second or third run (we typically did three runs whenever we made a change to ensure we eliminated any abnormalities.)

At this point we determined that the max HP was 110. We then spend some time attempting to modify the torque curve in the mid-range from 4600 rpm to 6200 rpm (see the dyno chart below). We tweaked the fueling a few times but could only manage to slightly reduce dip. We then surmised that the the dip was caused by one of two factors, or a combination of the two:

1) ignition timing; and/or
2) actuation of the flapper valve by the ECU.

Dynojet has a module you can buy to tinker with the timing, but I didn't want to go there. With respect to the flapper valve, it could have been replaced by a straight pipe (Wunderlich makes one) or we could have disabled it in the "open" position.

I was a bit curious as to the impact of the high-flow BMC re-usable air filter over stock. I had read in a number of forums that there was no meaningful impact, but never saw any facts supporting this position. So we decided to pull the BMC and put in the OEM filter and did three runs. We did 108 and 109 rwhp runs, and followed these up with a 111 rwhp run, which became the new high of the day! One caveat here - when we did the runs after the filter swap, we didn't replace the fairing. This allowed the cooling fans to blow directly up the snorkel, possibly providing a "ram air" effect.

I found this pretty conclusive evidence that "high-flow" air filters from K&N and BMC have little to no performance impact, but may still be worth buying as the re-usability factor will save you big bucks in the longterm. They are also beneficial as they allegedly continue to function when wet whereas paper filters break down. On the other hand, there are many posts in forums indicating that these high-flow filters are not recommended if you're doing significant dusty off-road riding because they tend to pass a lot of dust compared to the OEM paper filters

We then began discussing the size of the filter and the narrow snorkel. The dyno operators noted that the GS air filter was the smallest they've ever seen, and also found that the long, narrow-entrance snorkel may compound the problem of the engine being air-starved. So we removed the snorkel completely, and just had the BMC filter sitting in the airbox (again, with the fans blowing into the air filter). We did two runs, both hitting 105 rwhp. We then surmised that snorkel design was an integral part of the engine design and not to be messed with!

And with that my dyno session ended. I got my charts and rode home $350 broker.

Here's the dyno chart of my best stock run contrasting against the best run with the mods (the one with the stock air filter).

Vewy, vewy coo! Thank you for putting up the time and skrilla for the dyno runs.

A coupla questions:
1. Did the PC5/autotune fix the 4200 shakes? My bike has the same jitters with or without the ICE2 and with or without the flapper valve.
2. How much did your fuel economy change? Does the lean map help?

I take it you loaded a canned map and let the autotune module handle the VEs? Do you have any idea what the PC did to the target Lambda and spark tables? Also, the PCV adjusts timing the same way it adjusts target AFR/Lambda and VE; through offsets. I take it you didn't change them from the canned tables?

It's my belief that by altering the main Lambda table and correcting the VEs, the motor would take a fair amount more timing. If I'm right, you could see a substantial improvement in smoothness, power, and economy.

Thanks for taking all the time & money to doing this! It will really help me out soon. Especially the tuning part.
FWIW, I now see why your exhaust was available so quickly. You got the SS headers with the Ti silencer. I opted for the Ti headers.
Edit: I just drew a blank, what is V E?

I decided to splurge for the Power Commander in the hopes of adding additional power in the mid-range to hopefully drop the rpms below 4200 at my highway cruising speed of 120 kmh. I paid $520 for the R1200GS PC-V and AT-300 dual-channel Autotune device from Revzilla after a price match. The AT-300 has two O2 sensors so I could tune each cylinder independent of the other. The other advantage of the Power COmmander is that it enables you to have two maps, so I can set one map for every-day use (towards the power side in the non-cruise range) and second, leaner map to improve fuel economy on longer highway journeys. Creating the second map would be a snap with the Autotune.

...

The PCV comes with a map for the stock GS. Fortunately DynoJet had a map on its website for a US bike with a full Akro system and stock air filter, so I grabbed that. Turns out it was almost a perfect map for my bike.

After the installation of the mods was complete, I took the bike for a spin. My Fat Ass dyno certainly noticed the power pick-up as soon as it hit 6,000 rpm. The first time I cracked it wide open throttle, the bike nearly ripped the handlebars from my grip. It is literally like somebody threw the nitro switch at the engine crested 6,000 rpm. What an amazing feeling!

This is about when we first noticed that the performance of the boxer engine was highly temperature dependent. The best runs came when the engine was in the "high four bar" range, meaning just before the oil temperature gauge moved to five bars. Runs at three bars were consistently about 10-12 rwhp low (i.e. in the high 90's). Runs at five bars were typically around 4-5 rwhp low of the highs. The optimum readings all came during runs when the engine had been in the four bar range for a bit, and typically in the second or third run (we typically did three runs whenever we made a change to ensure we eliminated any abnormalities.)

...

Here's the dyno chart of my best stock run contrasting against the best run with the mods (the one with the stock air filter).

Click to expand...

Really interesting project thanks for providing all the information. I bet you're pretty pleased with the extra horses and better driveability. A couple questions and thoughts crossed my mind as I read through.

--Have you used the AutoTune capability yet? What's it like to use, how long did it take to dial it in?

--I see that the Dyno runs show data starting at 4000 RPM. Did you get any charts with data in t he 2000-4000 RPM range?

--I downloaded a map for the Akro system (attached below) I noticed that it adds a lot of fuel at half throttle. No real comment just found that some of the 25% additions are pretty big (if I'm reading it correctly). Also found it interesting that the L/R cylinders are pretty different.

--Regarding the best runs being just before it warmed up at 4 Bars, this may be at the tail-end of the warm-up enrichment and the BMS-K could be adding 3-4% to the fueling. If that's the case, you may get more performance warmed-up with some tweaks to the tables.

Thanks for taking all the time & money to doing this! It will really help me out soon. Especially the tuning part.
FWIW, I now see why your exhaust was available so quickly. You got the SS headers with the Ti silencer. I opted for the Ti headers.
Edit: I just drew a blank, what is V E?

The high-flow BMC air filter provided no performance gains to the subject motorcycle. In fact, of the 20+ runs we did, only two were with the stock filter and it was one of these runs where the bike achieved 111 rwhp. If you're buying the filter for its reusability and wet weather utility improvements over the OEM paper filter, then you're buying it for the right reasons. If you've drank the Kool-Aid and are buying it to give you increased power, you've been suckered.

4) The airbox snorkel appears to be an integral part of the air intake design. Out of curiosity, we removed the snorkel, thinking it may restrict air flow through the already quite small air filter. We did two runs and both were in the 105 rwhp range, down 5-6 rwhp from our high run.

Click to expand...

The BMC is no different then a K&N, which has been tested against paper and Uni Filter AUS foam to flow over 50cfm less then the Uni on a flow bench. I've also tested the Uni on R1200GS SIHC bikes with full exhaust systems and a tuner, the Uni did provide up to 3 additional rwhp with stock snorkel.

WL offered a "big mouth" snorkel for the Boxers, however I have not seen it of late and not dyno tested myself.

Also your dyno of choice is very generous as most dynojets around these parts put a stock R1200GS DOHC in the 90-94 rwhp stock with up to 104 after full Akra, PC V and Unifilter.

FWIW, I now see why your exhaust was available so quickly. You got the SS headers with the Ti silencer. I opted for the Ti headers.

Click to expand...

Your comments made me scratch my head. I wasn't aware there were two different full Akro exhaust systems differentiated by header materials, but it makes sense because Revzilla always listed a range for their R1200GS full exhaust system.

I'm on metallurgist, but I can tell the difference between titanium and stainless steel and I installed a fuIl titanium exhaust system. The packing slip says its an Evolution exhaust system and the installation manual is for a full titanium exhaust system (different instructions because there are two different anit-sieze products for the full ti system.)

I can't tell from my order form which system I ordered, I priced matched the exhaust system with one from another online dealer so maybe it was a full Ti system that I was unaware of or maybe Revzilla read the price match web site incorrectly. Maybe some dolt in shipping grabbed the incorrect box, or maybe Revzilla was giving me a free upgrade for ordering $3,000 of parts from them that week. Dunno, but what I do know is that I have a full Ti system. The weight savings alone confirms this.

I haven't had time to take the bike for a long ride to test the 4200 rpm shakes issue or to calculate the fuel economy. I'm not a big fuel economy aficionado on motorcycles, so I haven't take many mileage sessions to test fuel economy. I did calculate the mileage of two tanks of gas running a stock bike registered 42 mpg on both. The riding style was quite mixed for both rides - some highway, some back roads, some single track, etc. A very good "mixed riding conditions" ride.

I take it you loaded a canned map and let the autotune module handle the VEs? Do you have any idea what the PC did to the target Lambda and spark tables? Also, the PCV adjusts timing the same way it adjusts target AFR/Lambda and VE; through offsets. I take it you didn't change them from the canned tables?

Click to expand...

You can buy yet another Power Commander add-on that tunes in the ignition timing, but I gotta draw the line somewhere. I agree that if we had some spark timing flexibility we could have done a lot more. But time is money on the dyno and I was rapidly running out!

--Have you used the AutoTune capability yet? What's it like to use, how long did it take to dial it in?

Click to expand...

This is a good question. We used the Autotune extensively in the tuning. In our first few runs we used the trace function and ran through as many of the cells as possible to get the Autotune to register a trim adjustment. Most adjustments were in the low single digits.

Afterwards we would focus on an area of the map to tweak. We would set a target AFR (i.e. make a group of four cells) either richer or leaner and then do a few runs to see the difference in output. We would then make tweak the cells depending on the dtno run and Autotune trim table.

--I see that the Dyno runs show data starting at 4000 RPM. Did you get any charts with data in t he 2000-4000 RPM range?

Click to expand...

Another good question that requires an explanation of the dyno process. The test run is done in third gear which they determine is the optimal gear so the run doesn`t last too short or too long (and some other reasons undoubtedly). They would get the bike at a steady speed (in this case 4000 rpm) and then go to wide open throttle (wot). The operators chose 4k rpm because they mostly tune sport bikes on the dyno and they would often bog down below 4k rpm in third gear, ruining your run.

At one point when we were trying to reduce the mid-range dip we postulated that the first bump at 4800 rpm way have been as a result of transients caused when cracking the throttle open at 4k rpm. So given the massive torque put out by the Boxer, we decided we could safely start the run at 3k rpm to see if it made any difference to the first hump. It did not so we went back to 4k rpm for the remainder of the tests.

--I downloaded a map for the Akro system (attached below) I noticed that it adds a lot of fuel at half throttle. No real comment just found that some of the 25% additions are pretty big (if I'm reading it correctly). Also found it interesting that the L/R cylinders are pretty different.

Click to expand...

Accurate observation, and the Autotune did not significantly alter this map. I postulate that the factory may really lean this section of the stock map out, probably because it plays a big part in the EPA test. I don`t think the EPA test hits the WOT range and therefore there isn't as much adjustment there. As well, when riders crack open the throttle to 100%, they want to (or expect to) accelerate rapidly and are less forgiving of hesitations, boggings, etc. Just my guess.

Now that you mention it, I do recall they had another R1200GS in that did mid-90s. Don't recall if it was a DOHC boxer or the predecessor. This would be consistent with what you said.

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Sorry - I mis-spoke here. I realize now it was a forum member that sent me a PM a few days before my dyno session saying that he knew someone that did 94 rwhp stock and 104 rwhp with mods. Don't know if that's a DynoJet dyno or a Mustang dyno.

Your comments made me scratch my head. I wasn't aware there were two different full Akro exhaust systems differentiated by header materials, but it makes sense because Revzilla always listed a range for their R1200GS full exhaust system.

I'm on metallurgist, but I can tell the difference between titanium and stainless steel and I installed a fuIl titanium exhaust system. The packing slip says its an Evolution exhaust system and the installation manual is for a full titanium exhaust system (different instructions because there are two different anit-sieze products for the full ti system.)

I can't tell from my order form which system I ordered, I priced matched the exhaust system with one from another online dealer so maybe it was a full Ti system that I was unaware of or maybe Revzilla read the price match web site incorrectly. Maybe some dolt in shipping grabbed the incorrect box, or maybe Revzilla was giving me a free upgrade for ordering $3,000 of parts from them that week. Dunno, but what I do know is that I have a full Ti system. The weight savings alone confirms this.

bigbadandugly

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I believe you now. You are correct in that. I'm not sure what happened, but you got one hell of a deal, because I believe someone screwed up. At $1150 I assumed that was the SS version. That is about the on line price I've seen for it. The cheapest I found the Ti was $1500 on line, which is what my local guy price matched. I even checked Revzilla. I usually buy from them for stuff my local guy doesn't have in stock.